Processes for the preparation of fluorinated olefins and hydrofluorocarbons using fluorinated olefin

ABSTRACT

The invention relates to a cost effective and convenient process for the manufacture of fluorinated olefins of the formula RCF 2  CH=CH 2  where R is C x  Cl y  F z  and y+z=2×+1. The invention is also directed to a lo practical process for converting these olefins to hydrofluorocarbons via the catalyzed fluorination with hydrogen fluoride. Hydrofluorocarbons produced via this process have application as solvents among other uses.

This application is a division of application Ser. No. 08/242,899, filedMay 16, 1994.

BACKGROUND OF THE INVENTION

The invention relates to a cost effective and convenient process for themanufacture of fluorinated olefins of the formula RCF₂ CH=CH₂ where R isC_(x) Cl_(y) F_(z) and y+z=2×+1 which may be used as starting materialsfor the manufacture of hydrofluorocarbons. The invention is alsodirected to a practical process for converting these olefins tohydrofluorocarbons via catalyzed fluorination with hydrogen fluoride.The hydrofluorocarbons produced via this process have utility, amongother things, as solvents.

Traditionally, chlorofluorocarbons (CFCs) like trichlorofluoromethane(CFC-11), dichlorodifluoromethane (CFC-12 ) and1,1,2-trichloro-1,2,2-trifiuoroethane (CFC-113) have been used assolvents, refrigerants, blowing agents and diluents for gaseoussterilization. These materials, however, are suspect since they arebelieved to contribute to the stratospheric ozone depletion problem. Thefiuorocarbon industry has therefore focused its attention on developingstratospherically safer alternatives to these materials.Hydrofiuorocarbons (HFC's)like CF₃ CF₂ CH₂ CH₂ F (HFC-356 mcfq), whichhas been identified as a solvent, are candidate replacement materialssince they have no ozone depletion potential, contribute negligibly toglobal warming and offer substantially the same performance advantagessuch as nonflammability. As a result, methods for the manufacture ofthese materials need to be developed.

A few methods for the manufacture of compounds of the formula RfCH=CH₂where Rf is C_(n) F_(2n+1) are known in the art. See, e.g., U.S. Pat.No. 4,058,573 and Brace et. al., Effect of a perfluoroalkyl group on theelimination and substitution reactions of two homologous series ofperfluoroalkyl-substituted iodoalkanes, 49 J. Org. Chem., 2361 (1984).These references disclose the addition of a perfluoroalkyl iodide toethylene to yield RfCH₂ CH₂ l, followed by dehydroiodination to providethe olefin, RfCH=CH₂. This method is convenient only for the preparationof small quantities of materials because of the prohibitively high costof the perfluoroalkyl iodide.

U.S. Pat. Nos. 2,889,379 ('379 patent), 4,798,818 ('818 patent), and4,465,786 ('786 patent) disclose the preparation of CF₃ CH=CH₂ by thecatalyzed vapor phase fluorination of various halogen-containing C₃compounds such as CCl₃ CH₂ CH₂ Cl. These references however, do notteach or suggest that higher molecular weight homologs can be preparedby this method.

The halogen exchange in the precursors to the fluorinated olefins of ourinvention is dissimilar to the halogen exchange reported in thesereferences. That is, the references are replacing the chlorine in a-CCl₃. group with fluorine while we are replacing the chlorine in a -CF₂CCl₂ CH₂ group with fluorine. U.S. Pat. No. 4,078,007 discloses theliquid phase antimony pentachloride catalyzed fluorination with HF ofCCl₃ CH₂ CH₂ Cl (the same compounds used in the '379, '818 and '786patents) to provide CF₃ CH₂ CH₂ Cl at reaction temperatures of about 85°C. However, the liquid phase antimony pentachloride catalyzedfluorination with HF of CF₃ CCl₂ CH₂ CH₂ Cl (a precursor of thefluorinated olefins of our invention) even at substantially higherreaction temperatures failed to result in even modest fluorination. Thatis, of the product recovered, 97% was starting material. See ComparativeExamples 1 and 2.

As far as methods for the synthesis of HFC's from fluorinated olefins isconcerned, Henne et al., Influence of a CF₃ group on an adjacent doublebond, 72 J. Am. Chem. Soc., 3369 (1950) report that the CF₃ group in CF₃CH=CH₂ adversely affects the rate of addition of acids, HX where X is Bror Cl, to the carbon-carbon double bond. That is, Lewis acid catalystsand elevated temperatures are required to force these additions and eventhen modest yields and/or conversions may be obtained.

We have discovered: 1) a novel method for the production of fluorinatedolefins and 2) a novel method for the manufacture of various HFC's usingthese fluorinated olefins as starting materials which overcome thedrawbacks of the prior art processes discussed above.

DESCRIPTION OF THE INVENTION

This invention relates, in part, to a cost effective and convenientprocess for the manufacture of compounds of the formula RCF₂ CH=CH₂where R is C_(x) Cl_(y) F_(z) and y+z=2×+1. Preferably, the inventionrelates to preparation of compounds of the formula RCF₂ CH=CH₂ where Ris C_(x) Cl_(y) F_(z) and where x<4 and y<2 such as CF₃ CF₂ CH=CH₂, CF₃CF₂ CF₂ CH=CH₂, and (CF₃)CFCF₂ CH=CH₂ comprising:

a) reacting a compound of the formula RCX_(a) F_(b) ; where R=C_(m)X_(n) F_(o), m<4,n<2, m+o=2m+1, X=Cl or Br, a=2-3, and b=0-1, withethylene in the presence of an addition catalyst and a solvent underconditions sufficient to produce a compound of the formula RCX_(a-1)F_(b) CH₂ CH₂ X where X=Cl or Br, a=2-3 b=0-1 and a+b=3;

b) reacting a compound of the formula RCX_(a-1) F_(b) CH₂ CH₂ X whereX=Cl or Br, a=2-3, b=0-1 and a+b=3r with hydrogen fluoride in thepresence of a fluorination catalyst under conditions sufficient toproduce a compound of the formula RCF₂ CH=CH₂ where R is C_(x) Cl_(y)F_(z) where y+z=2×+1; and

c) recovering a compound of the formula RCF₂ CH=CH₂ where R is C_(x)Cl_(y) F_(z) and y+z=2 +1.

The starting material for the addition reaction, i.e., ethylene andcompounds of the formula RCX_(a) F_(b) ; where R=C_(m) X_(n) F_(o), m<4,n<2, m +o=2m+1, X=Cl or Br, a=2-3, b=0-1, and a+b=3 are commerciallyavailable from AlliedSignal Inc. or other domestic chemicalmanufacturers. Alternately, they may be synthesized by methods wellknown in the art. Suitable halogenated starting materials include, butare not limited to,: CF₃ CCl₃, CF₂ ClCFCl₂, CF₃ CF₂ CCl₃, ClCF₂ CF₂CCl₃, CCl₃ CF₂ CCl₃, CF₂ BrCF₂ CFBr₂, CF₃ CCl₂ CF₂ CCl₃, (CF₃)(CF₂Cl)CFCCl₃, (CF₃)₂ CFCCl₃, ClCF₂ CFClCF₂ CFCl₂. Preferred startingmaterials include: CF₃ CCl₃, CF₂ ClCFCl₂, ClCF₂ CF₂ CCl₃ and CCl₃ CF₂CCl₃.

Any commercially available catalyst known in the art to be useful incatalyzing the addition of halocarbons to olefins may be employed.Suitable addition catalysts include, but are not limited to, copper (I)salts such as cuprous chloride and cuprous iodide, iron (II) salts suchas ferrous chloride and ferrous acetate, and metal carbonyls such asiron carbonyl and cobalt carbonyl. Cuprous chloride is preferred.Optionally, any well known co-catalyst useful in catalyzing the additionof halocarbons to olefins may be employed in the reaction. Suitableaddition co-catalysts include aliphatic or aromatic amines such aspyridine and diethylamine.

Any inert solvent which can dissolve the catalyst and is miscible withthe halocarbon may be used in the reaction. Suitable solvents include,but are not limited to, commercially available low molecular weightnitriles such as acetonitrile and propionitrile, low molecular weightalcohols such as tertiary butanol and isopropanol, and amides such asdimethylformamide. Acetonitrile is preferred because of ease of handlingand stability.

The temperature at which the addition reaction is conducted and theperiod of reaction will depend on the starting material and catalystused. One of ordinary skill in the art can readily optimize theconditions of the reaction without undue experimentation to get theclaimed results but the temperature will generally be in the range offrom about 50 to about 150° C. for a period of from about 8-72 hours.When the starting material is one of the preferred compounds and thecatalyst is cuprous chloride, the reaction may be conducted at atemperature of from about 80-150° C. for a period of from about ₂₄ toabout 48 hours. Preferably, such a reaction would be conducted at atemperature of from about 125 to about 150° C. for a period of fromabout 8 to about ₃₀ hours.

Pressure is not critical.

Preferably the reaction is conducted in an apparatus made of corrosionresistant materials such as Teflon and glass.

Preferably, the addition product is recovered from by-products, solventand catalyst prior to the fluorination reaction to substantiallyeliminate the production of by-products in the fiuorination step.Preferably, the addition product should be about 95% pure. Morepreferably, the addition product should be about 98% pure. The additionproduct may be recovered by any means well known in the art such asdistillation and extraction. See, for example, Examples 1 and 2 below.

Compounds of the formula RCX_(a-1) F_(b) CH₂ CH₂ X where X=Cl or Br ,a=2-3, and b=0-1, a+b=3 are the starting material for the fluorinationreaction. They may be prepared as discussed above. Preferred startingmaterials include CF₃ CCl₂ CH₂ CH₂ Cl, ClCF₂ CFClCH₂ CH₂ Cl, and ClCF₂CF₂ CCl₂ CH₂ CH₂ Cl.

Commercially available hydrogen fluoride (HF) may be used in thefluorination reaction. Preferably, the HF is anhydrous. By "anhydrous"we mean that the HF contains less than about 1 wt % water and preferablycontains less than about 0.5 wt % water and more preferably containsless than about 0.02 wt % water. HF suitable for use in the reaction maybe purchased from AlliedSignal Inc. of Morristown, N.J.

Any well known vapor phase fluorination catalyst may be used in thefiuorination reaction. Suitable fiuorination catalysts include thefollowing catalysts and mixtures thereof: metal oxides such as chrome(III) oxide, supported metal oxides such as chrome (III) oxide supportedon aluminum oxide or carbon and supported metal halides such as cobalt(II) chloride and nickel (II) chloride supported on carbon, aluminumoxide, aluminum fluoride, or a mixture of such support materials, suchas a mixture of Cr₂ O₃ and Al₂ O₃. Chrome (III) oxide is preferred dueto its level of reactivity and commercial availability. Suitable chrome(III) oxide catalysts may be purchased from Mallinckrodt SpecialtyChemicals Co. of St. Louis, Mo.

Over time, the catalyst activity may diminish. In the case where suchdeactivation is caused by coking, the catalyst may be reactivated, forexample, by heating in a stream of air or oxygen. If chrome (III) oxideis the catalyst, following reactivation, the catalyst is preferablypretreated according to the process set forth in Example 3a.

One of ordinary skill in the art can readily optimize the conditions ofthe reaction without undue experimentation to get the claimed results.Generally, the organics, HF and fluorination catalyst are reacted at atemperature in the range of from about 150° to about 350° C.,preferably, from about 200° to about 275° C. and most preferably fromabout 225° to about 250° C. with a contact time of, for example, about0.1 to about 240 seconds, preferably from about 1 to about 100 secondsand most preferably from about 5 to about 50 seconds. For purposes ofthis invention, contact time shall mean the time required for thegaseous reactants to pass through the catalyst bed assuming that thecatalyst bed is 100% void.

The molar ratio of HF to organics will depend on the number ofnonfluorine halogens in the starting material. Generally, the mole ratioof HF to organics will be from about 1 to about ₃₀ moles HF per mole ofnonfluorine halogen present. See Examples 3-6.

Pressure is not critical. Atmospheric and super atmospheric pressure arethe most convenient and are therefore preferred. In particular, highreaction pressure is desirable because it makes separation of the HFfrom HCl easier.

The reaction is preferably conducted in an apparatus made of corrosionresistant material such as Inconel or Monel.

In another embodiment, the invention relates to a process for preparingHFC's comprising:

1) reacting a compound of the formula RCF₂ CH=CH₂ where R is C_(x)Cl_(y) F_(z) and y+z=2×+1 with hydrogen fluoride in the presence of anantimony (V) halide catalyst under conditions sufficient to produce acompound of the formula RCF₂ CH₂ CH₂ F where R is C_(x) Cl_(y) F_(z) ;and y+z =2×+1; and

2) recovering a compound of the formula RCF₂ CH₂ CH₂ F where R is C_(x)Cl_(y) F_(z) and y+z=2×+1.

The fluorinated olefin starting material is selected based upon thedesired HFC to be produced. For example, if one wanted to produce CF₃CF₂ CH₂ CH₂ F, then one would use CF₃ CF₂ CH=CH₂ as the startingmaterial.

Any water in the HF will react with and deactivate the antimony (V)halide catalyst. Therefore, substantially anhydrous HF is preferred. By"substantially anhydrous" we mean that the HF contains less than about0.05 wt % water and preferably contains less than about 0.02 wt % water.However, one of ordinary skill in the art will appreciate that thepresence of water in the catalyst can be compensated for by increasingthe amount of catalyst used. HF suitable for use in the reaction may bepurchased from AlliedSignal Inc. of Morristown, N.J.

Any antimony (V) halide, antimony (V) mixed halide, or mixtures ofantimony (V) halide catalysts may be used in the fluorination reaction.Examples of antimony (V) halide catalysts include antimony pentachlorideand antimony pentafluoride. Examples of antimony (V) mixed halidesinclude SbCl₂ F₃ and SbBr₂ Cl₃. Examples of mixtures of antimony (V)halide catalysts include a mixture of antimony pentachloride andantimony pentafluoride. Antimony pentachloride is preferred because ofits low cost and availability.

The temperature at which the organics, hydrogen fluoride andfluorination catalyst are reacted is critical. If the temperature is toolow (i.e., <-20° C.), the desired reaction is very slow, but if it istoo high (i.e., >20° C.) undesirable side reactions occur, which includethe reverse reaction, which reduces yield. Thus, it is preferred to runthe reaction at a temperature of from about -20 ° to about °20° C. Areaction temperature of from about -10° to about 10° C. is morepreferred and a reaction temperature of from about -5° to about 5° C. ismost preferred.

The stoichiometric molar ratio of HF to organics in the fluorinationreaction is 1:1. However, in order to dissolve the catalyst and controlreaction temperature, the HF is preferably used in excess i.e., e.g.,from about 10-20:1 HF:organics.

Atmospheric or superatmospheric pressure is preferred.

The reaction is preferably conducted in an apparatus made of corrosionresistant material such as Inconel, Monel or Teflon.

EXAMPLE 1 Addition of CF₃ CF₂ CCl₃ to ethylene to produce CF₃ CF₂ CCl₂CH₂ CH₂ Cl

A Teflon-lined autoclave was charged with 137 g of cold CF₃ CF₂ CCl₃, 1g Cul, 20 mL cold CH₃ CN, and 3 mL pyridine, and evacuated briefly.Ethylene (18.3 g) was then charged and the contents heated to 137° C.for 6 h. After allowing the contents to cool, the volatiles were vented,and the contents were poured into 100 mL 1 N HCl. The organic layer waswashed with cold water (100 mL) and dried (CaCl₂). Distillation provided87 g of a colorless liquid which was identified spectroscopically as CF₃CF₂ CCl₂ CH₂ CH₂ Cl (bp 71°-73° C. at 75-6 mm Hg). ¹ H NMR: equalintensity triplets at δ 3.93 and 2.82; ¹⁹ F NMR: -77.3 (3 F) and -117.5(2 F) ppm; IR: strong bands at 1225, 1185, 1160 cm⁻¹. Gas chromatographydetermined that the product was 99.6% pure.

EXAMPLE 2 Addition of CF₃ CCl₃ to ethylene to produce CF₃ CCl₂ CH₂ CH₂Cl

A 600 mL stirred Monel autoclave was charged with 30 mL CH₃ CN, 3 mLpyridine, 1 g Cul, and 199.6 CF₃ CCl₃. The contents were cooled to -29°C., the autoclave briefly evacuated, and charged with 24.4 g ethylene.The contents were then heated to 135°-145 ° C. for 22 h. After coolingthe contents, the volatiles (unreacted ethylene) were vented. Theresidue was diluted with ₃₀₀ mL water, and extracted with 50 mL CH₂ Cl₂.The organic layer was then washed twice with 50 mL 5% aqueous HCl, twicewith 50 mL 5% NaOH, twice with 50 mL water and finally dried (CaCl₂).Distillation at 145 mm Hg gave 80 g (58% yield) of a colorless liquidwhich was identified spectroscopically as CF₃ CCl₂ CH₂ CH₂ Cl (bp102°-103 ° C.). ¹ H NMR: equal intensity triplets at δ 3.9 and 2.77; ¹⁹F NMR: -81 (s) ppm; IR: strong bands characteristic of CF₃ CCl₂ CH₂ -grouping at 1255, 1210, and 1180 cm⁻¹. Gas chromatography determinedthat the product was 99% pure. CF₃ CCl.sub. 2 CH₂ CH₂ Cl has utility asan intermediate in the preparation of fluroinated olefins of theinvention which may be used to prepare hydrofluorocarbons. See Example 3below.

EXAMPLE 3 Vapor phase fluorination of CF₃ CCl₂ CH₂ CH₂ Cl to produce CF₃F₂ CH=CH₂.

(a) Catalyst Pretreatment. While maintaining a nitrogen flow of 350mL/min through a 1 inch pipe reactor, pelletized chrome oxide (Cr₂ O₃),(available from Mallinckrodt Specialty Chemicals Co., St. Louis, Mo.)was heated to 350° C. at a rate of 50 C/h, maintained at 350° C. for 8h, then cooled to 200° C. at a rate of 40 C/h. Liquid hydrogen fluoridewas then metered in at a rate to keep the temperature below 250° C.(about 0.8 cc/min). After the exotherm had moved through the catalystbed, the temperature was again increased to 350° C. at a rate of 50 C/h,and held at 350° C. for 2 h. Finally, the temperature was decreased to250° C. at a rate of 50 C/h.

(b) Fluorination Reaction. The pretreated catalyst (150 cc) was heatedto 250° C. in the reactor while passing HF into the reactor at 1.4mL/min at an operating pressure of 50 psig. The organic, CF₃ CCl₂ CH₂CH₂ Cl, was then fed at 0.7 g/min (contact time 10 sec). Gaschromatographic analysis of the reactor effluent indicated an 83%conversion of starting material. The products, which were collected in a-78° C. cold trap and identified by GC-MS, included CF₃ CF₂ CH=CH₂(23.4%), C₄ H₃ ClF₄ isomers (5.5%), CF₃ CF₂ CH₂ CH₂ Cl (4.4%), CF₃ CCl₂CH₂ CH₂ F (2.1%), and C₄ H₃ Cl₂ F₃ isomers (62.9%). The desired olefin,CF₃ F₂ CH=CH₂ (bp 3°-6° C.) was readily recovered in high purity fromthe crude product by bulb-to-bulb distillation. The C₄ H₃ Cl₂ F₃ isomerswere later separated via distillation using a three-foot packed columnand identified as follows: fraction boiling at 95°-101° C. consisted of10% CF₃ CCl₂ CH₂ CH₂ F and CF₃ CCl=CHCH₂ Cl (86 and 4% respectively);fraction boiling at 101° C. consisted of CF₃ CCl₂ CH₂ CH₂ F (3%) and amixture of cis- and trans- CF₃ CCl=CHCH₂ Cl (92 and 5%). ¹ H NMR for CF₃CCl₂ CH₂ CH₂ F: δ 2.74 (dt, CH₂ CH.sub. 2 F, JH-F=18.6 Hz, JH-H=6.3 Hz)and 4.83 (dr, CH₂ CH₂ F, JH-F=46.2 Hz, JH-H=6.3 Hz);¹⁹ F NMR: -80.7 and-222.4 ppm. ¹ H NMR for CF₃ CCl=CHCH₂ Cl: δ 6.61 (=CH, JH-H=7.2 Hz,JH-F=1.0 Hz) and 4.24 (CH₂ Cl, JH-H=7.2 Hz, JH-F=0.5 Hz); ¹⁹ F NMR:-70.6 ppm. Cis- and trans- CF₃ CCl=CHCH₂ Cl are useful as startingmaterials for the manufacture of hydrofluorocarbons which mayapplication as solvents among other things.

(c) Recycle of underfluorinated (chlorinated by-products) materials. Theby-products recovered above, specifically a mixture containing 7.5% CF₃CCl₂ CH₂ CH₂ F and 92.3% cis- and trans-CF₃ CCl=CHCH₂ Cl were placedinto the reactor and then passed over 150 cc of the catalyst at 50 psigand a temperature of 225° C. HF feed rate was 1.4 cc/min, while theorganic feed rate was 0.7 g/min corresponding to a contact time of about10 sec. Gas chromatographic analysis of the reactor effluent indicatedthat it was comprised of 79% CF₃ CF₂ CH=CH₂. This indicated to us thatCF₃ CCl=CHCH₂ Cl must be an intermediate in the vapor phase fluorinationof CF₃ CCl₂ CH₂ CH₂ Cl to CF₃ CF₂ CH=CH₂. Were it otherwise, the yieldof CF₃ CF₂ CH=CH₂ would have been much lower, reflecting thefluorination of only 7.5% CF₃ CCl₂ CH₂ CH₂ F.

EXAMPLES 4-7 Vapor phase fiuorination of CF₃ CCl₂ CH₂ CH₂ Cl to produceCF₃ F₂ CH=CH₂.

The experiment reported in Example 3 was repeated using thetemperatures, pressures and contact times reported in Table I below.

                  TABLE 1                                                         ______________________________________                                                     4        5      6                                                ______________________________________                                        Pressure (psig)                                                                              100        200     200                                         Temperature (C.)                                                                             200        225     250                                         Contact time (s)                                                                              18         32      30                                         Conversion (%)  60         73      79                                         Selectivity (%) for                                                           CF.sub.3 CF.sub.2 CH.sub.2 CH.sub.2 F                                                         1          1       1                                          CF.sub.3 CF.sub.2 CH═CH.sub.2                                                              22.1       18.1    23.4                                      CF.sub.3 CCl═CHCH.sub.2 Cl                                                                 74.2       78.1    72.5                                      Other             2.7        2.8     3.1                                      ______________________________________                                    

These Examples show that there is a range of operating conditions thatgive useful quantities of a desired olefin.

EXAMPLE 7 Hydrofluorination of CF₃ CF₂ CH=CH₂ to produce CF₃ CF₂ CH₂ CH₂F.

A stirred PTFE reactor, connected to a CaSO₄ drying tube, a causticscrubber and a -78° C. cold trap, was charged with 3.2 g SbCl₅ and 55.0g HF at 0° C. Over a period of 4.75 h, 29.0 g CF₃ CF₂ CH=CH₂ was bubbledinto the HF solution. After stirring for an additional hour at 0° C.,the dark red reaction mixture was poured cautiously into ice-cold 5%aqueous KOH. The lower light brown organic phase (18.2 g) was analyzedusing gas chromotography and found to contain 70.0% CF₃ CF₂ CH₂ CH₂ F,14.3% CF₃ CF₂ CH₂ CHCl, and 15.7% of higher boiling materials (including8-carbon compounds). Distillation of a larger sample of crudeCF3CF2CH2CH2F provided pure material having the following properties: bp44°-45° C., ¹ H NMR: δ 4.69 (dr, J=46.4 and 5.6 Hz, CH2F) and 2.45 (m,CF2CH2); ¹⁹ F NMR: -87.1 (3 F), -118.6 (2 F, dt, J=17.8 and 6.4 Hz), and-223.1 (1 F) ppm.

The 8-carbon compounds produced as by-products in this reaction wereidentified by GC-MS as primarily isomeric olefins (2:1 ration) of themolecular formula C8H6F10. The major isomer was identified by NMRanalysis as CH₂ =C(CF₂ CF₃)CH(CH₃)(CF₂ CF₃), while the minor isomer wasCF₃ CF₂ CH₂ CH=C(CH₃)(CF₂ CF₃). ¹ H NMR for the major isomer: δ 1.3 (d,CH3, 3JH-H=7 Hz), 3.0 (m, -CH(CH₃), 5.8 (dt,=CHH, J=16 and 11 Hz), and6.38 (dd,=CHH, J=16 and 9 Hz); ¹⁹ F NMR: -83.7 (s, 3 F), -87.1 (s, 3 F),-117.8 (d, 1 F), -118.0 (d, 1 F, J=11 Hz), -121.0 (dd, 1 F, J =271 and11 Hz), and -124.6 (dd, 1 F, J= 271 and 18 Hz) ppm. ¹ H NMR for theminor isomer: δ 1.85 (s, 3 H), 3.0 (m, 2 H), and 6.15 (t, 1 H, J=7 Hz);¹⁹ F NMR: -85.5 (s, 3 F), -86.9 (s, 3 F), -188.2 (t, 2 F, J=16 Hz), and-119.0 (s, 2 F) ppm.

COMPARATIVE EXAMPLE 1 Fluorination of CF₃ CCl₂ CH₂ CH₂ Cl with HF/SbCl₅.

A monel autoclave was charged with 5.6 g SbCl₅, 29.8 HF, and 54.2 g CF₃CCl₂ CH₂ CH₂ Cl. The contents were stirred and heated to 175° C. for 14h. The contents were vented into a caustic scrubber, followed by a -78°C. cold trap. Product was recovered from the cold trap and the scrubberand analyzed using gas chromatography. Product recovered from thescrubber was o identified as 40.8 g of starting material (98% purity).The 2.2 g of product from the cold trap also identified as primarilystarting material.

COMPARATIVE EXAMPLE 2 Fluorination of CF₃ CCl₂ CH₂ CH₂ Cl with HF/SbCl₅at higher temperature.

The experiment outlined in Comparative Example 1 was repeated using thefollowing materials and reaction conditions: 9.7 g SbCl₅, 36.2 g HF,32.3 g CF₃ CCl₂ CH₂ CH₂ Cl were mixed, stirred and heated at 225° C. for14 h. Results similar to those reported in Comparative Example 1 wereobtained; the scrubber contained 97% starting material, while the coldtrap contained a small amount of CF₃ CCl₂ CH=CH₂ and a C₄ H₄ F₄ Cl₂isomer. Thus, unlike CCl3CH2CH2Cl which fluorinated readily to CF₃ CH₂CH₂ Cl with HF and antimony pentachloride at modest temperature (85° C.)(U.S. Pat. No. 4,078,007), the CCl₂ group in CF₃ CCl₂ CH₂ CH₂ Cl wasresistant to fiuorination even at elevated temperature (>175° C.).

COMPARATIVE EXAMPLE 3

Hydrofluorination of CF₃ CF₂ CH=CH₂.

A monel autoclave was charged with 6.5 g SbF₅, 30 g HF, and 43.8 g CF₃CF₂ CH=CH₂. The mixture was heated to 105° C. for 12 h. Venting thereaction mixture into a caustic scrubber, followed by cold traps, gave33 g of product mixture, while the autoclave residue consisted of blackliquid and solid. Gas chromatographic analysis of the 33 g of organicproduct indicated that it contained 54% CF₃ CF₃ CH₂ CH₂ F, 33% of a C₈H₆ F₁₀ isomer, and 5% starting material.

COMPARATIVE EXAMPLE 4 Hydrofluorination of CF₃ CF₂ CH=CH₂.

The experiment outlined in Comparative Example 3 was repeated using thefollowing materials and reaction conditions: 3.9 g SnCl₄, 20 g HF, and43.8 g CF₃ CF₂ CH=CH₂ were mixed together and heated to 98-106° C. for 5h to give 40 g of liquid product which gas chromatographic analysisindicated consisted of 94% starting material.

COMPARATIVE EXAMPLE 5 Hydrofluorination of CF₃ CF₂ CH=CH₂.

The experiment outlined in Comparative Example 3 was repeated using thefollowing materials and reaction conditions: 8.5 g TaF₅, 40.3 g HF, and47.4 g CF₃ CF₂ CH=CH₂ were mixed together and heated to 108° C. for 17.5h to give 44.3 g of product which gas chromatographic analysis indicatedconsisted of 29% starting material, 1% CF₃ CF₂ CH₂ CH₂ F, 20% C₈ H₆ F₁₀,and 46% polymeric material.

These comparative examples show that use of Lewis acid catalysts andelevated temperatures (the teachings of Henne et el., discussed above)result in either little reaction or unacceptably large quantities ofbyproducts, such as higher boiling materials.

COMPARATIVE EXAMPLES 6-8 Hydrofluorination of CF₃ CF₂. CH=CH₂ at lowtemperatures with catalysts other than SbCl₅.

The experiment outlined in Example 7 above was repeated using each ofthe following Lewis acid catalysts: TiCl₄, SnCl₄, and BF₃. In each case,none of the desired CF₃ CF₂ CH₂ CH₂ F product was obtained and virtuallyno reaction occurred.

We claim:
 1. A compound of the formula CF₃ CF₂ CH₂ CH₂ F.
 2. A compoundof the formula CF₃ CCl=CHCH₂ Cl.
 3. A compound of the formula CF₃ CCl₂CH₂ CH₂ Cl.